AMPS 101

I would hold it to around 6A even at 18V. Most mini-toggles I have seen are not robust enough to handle more (internal melting if derailment/ short occurs). The regular toggles are more robust and are good for at least 10A, "heavy duty" can probably do 15A or 20A.

The voltage ratings usually have more to do with the type of contact make and break action.  I agree with the previous post, I have a bunch of relays that are rated at the same current for 30 or 110 volts.

Thanks! So, do you think a SPST on/off mini toggle can handle a Big Boy? I'm thinking of using them for several blocks with TPC400 and Lionel 180 bricks.

The problem is not handling the Big Boy, but rather the surge current when you have a derailment.  The brick will put out a big surge until the protection circuit cuts out.  That could burn or weld the contacts on the mini switch.

If you're considering two PH180's connected to that TPC400, we're talking in excess of 20 amps before the breakers would trip.  That's too much for the mini-switch, they're typically rated for 6A.

You could activate a relay with a toggle descried here

http://www.jcstudiosinc.com/Bl...=635&categoryId=

Dale H

But the TPC400 has a quick-acting breaker that I've seen work immediately. So it would break before the 180's would, right?

The TPC400 will allow 20+ amps to pass before it trips, and it doesn't have fast acting circuit breakers.  You need good circuit protection if you don't want to be replacing things.

Time to read about the TPC at TrainFacts.

"Immediately" is a relative term.  Both the Brick and the TPC have protection that operates fast to our thinking, but there can be a very large pulse of current for a while.  The thermal breaker in a TPC 400 is rated at 20 amps, but it is specified to trip in 2.2-15.0 seconds when overloaded with twice the rated current (40 amps in this case.)  Meanwhile, your mini switch is frying.

Thanks to all for the knowledge and sharing the helpful info. I appreciate it. Here's a hard-hat shot of where I am in the process.

Nice looking layout you have there.

I bought a bunch of really cheap micro push button and toggle switches years ago. Rating seemed fine to me. I used them a few months ago inline to yards and blocks and other things.

Big mistake. Many have stopped working. I replace them as it happens with solid ones. Use a good quality product and do it one time. Funny thing is the price difference between a good one and a cheap one is not that much anyway. 

They are fine for accessory lighting so I will use them that way. 

This set-up where two PH135 supply a TPC400 always, (always) opens the (2) 7.5amp overload resets on the PH135's on a dead short de-rail.  I have never had the 20 amp protection on the TPC open.   So the opening current is +15 amps enough to do significant arc and spark welding on my Atlas track.  I eventually installed a fused system for each power district @ 7.5 amps/ district (block).

Fuse blocks with 7.5 amp fuses max.

The early IC Controls BPC's pictured were rated at 15 amps The system OCP wasn't good enough to protect the BPC's, which required trace repair.